Hi,thanks for using HCM.. Primolut N tablets contain the active ingredient norethisterone, which is a synthetic hormone similar to the naturally progesterone. This medication is used to prolong the periods in women who are not pregnant. But this medication is not a contraceptive and does not inhibit ovulation, hence pregnancy can occur while a woman is taking this pills. Hence non-hormonal contraception (Barrier methods) have to be used as measures to prevent pregnancy while on this medication. In case, you do prefer to avoid pregnancy, and postpone the monthly bleeding use of progestogen-estrogen combinations is preferred, because the occurrence of a pregnancy is virtually ruled out by the inhibition of ovulation by such medications. You might consult your doctor who can prescribe you a proper hormonal combination medication that can act as a contraceptive as well as postpone your periods. Hope i have answered your question.. Good day